Coarse-Grained Analysis of Crystalline Defects Caused by Ion Beam Irradiation:PM (Pixel Mapping) Method

The radiotracer technique was applied for measuring grain boundary diffusion of Ni in ultrafine grained (UFG) copper materials with different nominal purities and in a Cu—1wt.%Pb alloy. The UFG specimens were prepared by equal channel angular pressing at room temperature. The stability of the microstructure was studied by focused ion beam imaging. Grain boundary diffusion of the 63Ni radioisotope was investigated in the temperature interval from 293 to 490K under the formal Harrison type C kinetic conditions. Two distinct short-circuit diffusion paths were observed. The first (relatively slow) path in the UFG materials corresponds unambiguously to relaxed high-angle grain boundaries with diffusivities which are quite similar to those in the respective coarse-grained reference materials. The second path is characterized by significantly higher diffusivities. The experimental data are discussed to elucidate the contribution of nonequilibrium grain boundaries in the deformed materials. Alternative contributions of other shortcircuit diffusion paths cannot be ruled out, particularly for the Cu-Pd alloy.

Download Full-text

Resolution-Enhanced Magnification of a Far Three-Dimensional Object Image by Using the Moving-Direct-Pixel-Mapping Method in Scalable Integral-Imaging System

Japanese Journal of Applied Physics ◽

10.1143/jjap.51.022501 ◽

2012 ◽

Vol 51 ◽

pp. 022501 ◽

Cited By ~ 1

Author(s):

Yongri Piao ◽

Miao Zhang ◽

Eun-Soo Kim

Keyword(s):

Imaging System ◽

Three Dimensional ◽

Mapping Method ◽

Object Image ◽

Integral Imaging ◽

Dimensional Object ◽

Pixel Mapping

Download Full-text

3D FIB and AFM mapping of Nanoindentation Zones

MRS Proceedings ◽

10.1557/proc-649-q3.7 ◽

2000 ◽

Vol 649 ◽

Cited By ~ 1

Author(s):

T.J. Steer ◽

G. Möbus ◽

O. Kraft ◽

T. Wagner ◽

B.J. Inkson

Keyword(s):

Focused Ion Beam ◽

Ion Beam ◽

Mapping Method ◽

Three Dimensions ◽

Mapping Technique ◽

Film Material ◽

Cross Sectional ◽

Data Set ◽

3D Data ◽

Computer Based

ABSTRACTA novel technique has been developed to examine site-specific, subsurface microstructures in three dimensions. A 3D data set is collected by successive cross-sectional slicing using a gallium focused ion beam (FIB) and imaging using ion-induced secondary electrons, enabling a 3D microstructure map to be generated using computer-based reconstruction techniques. In the first instance, this 3D FIB mapping technique has been applied to copper-based epitaxial metal multilayer coatings which have been deformed by nanoindentation. It is possible to produce 3D profiles of the deformed subsurface interfaces. These individual interface maps allow analysis of the deformation in terms of both the thickness of individual layers and that of the entire film. Material flow, which is seen as pile-up and residual indent zones around the indent, can thus be precisely characterised. The site at which the sectioning is to be carried out can be chosen with high spatial resolution; consequently, nanoscale mechanical properties can be linked directly with an area's microstructure.In an attempt to examine the errors involved in this 3D mapping method the 3D FIB map of the surface of a residual indent has been compared to an atomic force microscopy (AFM) scan of the same region. The sources and significance of the errors are discussed with reference to ways in which they might be reduced.

Download Full-text

Microstructural characterisation of the Ypresian clays (Kallo-1) at nanometre resolution, using broad-ion beam milling and scanning electron microscopy

Netherlands Journal of Geosciences – Geologie en Mijnbouw ◽

10.1017/njg.2016.16 ◽

2016 ◽

Vol 95 (3) ◽

pp. 293-313 ◽

Cited By ~ 4

Author(s):

S. Hemes ◽

G. Desbois ◽

J. Klaver ◽

J.L. Urai

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Power Law ◽

Ion Beam ◽

Coarse Grained ◽

Boom Clay ◽

Fine Grained ◽

Pore Size Distributions ◽

Clay Matrix ◽

Scanning Electron

AbstractBesides the Oligocene Boom Clay, the Ypresian clays – part of the Eocene Ieper Group (Kortrijk Formation and Kortemark Member) – are currently being investigated as an alternative host rock for the deep geological disposal of radioactive waste in Belgium and the Netherlands. In this study, broad-ion-beam milling and high resolution scanning electron microscopy (BIB-SEM) analyses were carried out to analyse the mineral fabrics and microstructures of representative Ypresian clay samples from different depths of the ON-Kallo-1 borehole (Kallo, Belgium). Qualitative microstructural observations indicate that mineral fabrics and pore morphologies in fine-grained samples are comparable to those found for fine-grained Boom Clay, but most of the Ypresian clay samples analysed also contained a significant silt fraction, which is associated with larger inter-aggregate pores, coated by a thin, very low porous clay layer. Quantitative pore-shape analysis shows lower axial ratios and elongations, as well as higher roundness and circularities for pores in the clay matrix of the more coarse-grained samples, compared to the fine-grained samples. The contribution of large pores (>1 × 107nm² pore area) to the total BIB-SEM observed porosity was found to correlate with the non-clay mineral (NCM) content of a sample. Frequencies of pore sizes within the clay matrix follow a power-law distribution, hinting towards the possibility of up-scaling of the nanometre-scale observations to larger scale (micro-) structural features of the material. Power-law exponents are comparable to values found for power-law pore-size distributions within the clay matrix of the Boom Clay, which indicates similarity of the pore-space morphologies within the clay matrix of the Boom Clay and the Ypresian clays. Wood's metal injection, followed by (cooled BIB)-SEM analysis shows that all visible pores are connected via pore throats of diameter down to ~10 nm.

Download Full-text